Endoscopic hook blade and use thereof

Abstract

An endoscopic surgical blade is disclosed. The blade is of a hook design, having an upper cutting surface located on the trailing edge of an arm and a lower cutting surface on the upper edge of the main body of the blade. The blade is part of an endoscopic knife assembly which also contains a knife tube and alignment ring. The endoscopic knife assembly is for use in endoscopic surgery by insertion of the assembly through a slotted cannula. The knife tube is hollow and allows the insertion of an endoscope for viewing of the surgical procedure. A method for a performing an operative procedure on a target tissue in a subject using an endoscopic knife assembly having a hook blade is also described.

What is claimed is: 
     
       1. A hook blade for an endoscopic surgical assembly comprising the blade and a tube marked with gradations showing distance, wherein the blade comprises:
 an arm having a forward edge that is a non-cutting surface, a trailing edge and an upper cutting surface located on the trailing edge; 
 a main body having an upper edge, a lower edge, a distal section, a proximate section, and a lower cutting surface located on the upper edge of the distal section; 
 wherein the distal section of the main body angles downward from the proximate section of the main body, forming a downward angle with the proximate section of the main body; 
 wherein the arm protrudes from the distal section of the main body, forming a hook angle with the proximate section of the main body, 
 wherein the upper cutting surface and the lower cutting surface meet at a crotch forming a cutting angle between the two cutting surfaces, 
 wherein the main body comprises a notch on the lower edge, 
 wherein the notch is on an opposite side of the blade from the upper cutting surface of the arm, 
 wherein the lower edge that includes the notch is in direct contact with a cylindrical surface of the tube marked with the gradations, and 
 wherein during a surgical procedure, relative positions of the gradations with respect to a location of the direct contact with the notch are visible. 
 
     
     
       2. The hook blade of  claim 1 , wherein the downward angle is between about 150 degrees and about 175 degrees. 
     
     
       3. The hook blade of  claim 1 , wherein the proximate section of the main body has a tapered end. 
     
     
       4. The hook blade of  claim 1 , wherein the arm comprises an upper radius on the upper end of the forward edge to prevent the forward edge from damaging tissue as the hook blade is advanced from a cannula. 
     
     
       5. The hook blade of  claim 4 , wherein the arm further comprises a lower radius on the lower end of the forward edge to prevent the forward edge from damaging tissue as the hook blade is advanced from a cannula. 
     
     
       6. The hook blade of  claim 1 , wherein the hook blade has a total vertical height in the range of about 4 mm to about 5 mm. 
     
     
       7. An endoscopic surgical assembly, comprising:
 a blade; and 
 a tube marked with gradations showing distance, 
 wherein the blade comprises a distal blade portion and a planar main body, 
 wherein the distal blade portion angles downward from the planar main body, forming a downward angle with the planar main body; 
 wherein the distal blade portion and the planar main body are connected at an interface to form the blade, 
 wherein the blade comprises a notch formed on a lower edge of the blade at the interface between the distal blade portion and the planar main body so that the notch defines the distal portion of the blade, 
 wherein the planar main body extends along an axis parallel to a longitudinal centerline of the tube of the endoscopic knife assembly, 
 wherein the distal blade portion includes a non-cutting surface formed as a radiused top edge facing away from the planar main body, and upper and lower cutting edges meeting at a crotch at the distal blade portion and forming a cutting angle between the two cutting edges, 
 wherein the lower edge of the blade is on an opposite side of the blade from the radiused top edge of the distal blade portion, 
 wherein the notch is on an opposite side of the blade from the radiused top edge of the distal blade portion, 
 wherein the lower edge that includes the notch is in direct contact with the cylindrical surface of the tube marked with the gradations, and 
 wherein during a surgical procedure, relative positions of the gradations with respect to a location of the direct contact with the notch are visible. 
 
     
     
       8. The endoscopic surgical assembly of  claim 7 , wherein the tube comprises one or more slots at a proximate end for the attachment of a locking assembly to the tube. 
     
     
       9. The endoscopic surgical assembly of  claim 8 , wherein the slots are located on a plane that is perpendicular to the blade attached to a distal end of the tube. 
     
     
       10. The endoscopic surgical assembly of  claim 7 , wherein the tube is marked on the top or side surface with gradations.